net: udp: introduce UDP_MIB_MEMERRORS for udp_mem

When udp_memory_allocated is at the limit, __udp_enqueue_schedule_skb
will return a -ENOBUFS, and skb will be dropped in __udp_queue_rcv_skb
without any counters being done. It's hard to find out what happened
once this happen.

So we introduce a UDP_MIB_MEMERRORS to do this job. Well, this change
looks friendly to the existing users, such as netstat:

$ netstat -u -s
Udp:
    0 packets received
    639 packets to unknown port received.
    158689 packet receive errors
    180022 packets sent
    RcvbufErrors: 20930
    MemErrors: 137759
UdpLite:
IpExt:
    InOctets: 257426235
    OutOctets: 257460598
    InNoECTPkts: 181177

v2:
- Fix some alignment problems

Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Link: https://lore.kernel.org/r/1604627354-43207-1-git-send-email-dong.menglong@zte.com.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Menglong Dong 2020-11-05 20:49:14 -05:00 committed by Jakub Kicinski
parent bff6f1db91
commit a3ce2b109a
5 changed files with 10 additions and 0 deletions

View File

@ -159,6 +159,7 @@ enum
UDP_MIB_SNDBUFERRORS, /* SndbufErrors */
UDP_MIB_CSUMERRORS, /* InCsumErrors */
UDP_MIB_IGNOREDMULTI, /* IgnoredMulti */
UDP_MIB_MEMERRORS, /* MemErrors */
__UDP_MIB_MAX
};

View File

@ -167,6 +167,7 @@ static const struct snmp_mib snmp4_udp_list[] = {
SNMP_MIB_ITEM("SndbufErrors", UDP_MIB_SNDBUFERRORS),
SNMP_MIB_ITEM("InCsumErrors", UDP_MIB_CSUMERRORS),
SNMP_MIB_ITEM("IgnoredMulti", UDP_MIB_IGNOREDMULTI),
SNMP_MIB_ITEM("MemErrors", UDP_MIB_MEMERRORS),
SNMP_MIB_SENTINEL
};

View File

@ -2038,6 +2038,9 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
if (rc == -ENOMEM)
UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
is_udplite);
else
UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS,
is_udplite);
UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
kfree_skb(skb);
trace_udp_fail_queue_rcv_skb(rc, sk);

View File

@ -126,6 +126,7 @@ static const struct snmp_mib snmp6_udp6_list[] = {
SNMP_MIB_ITEM("Udp6SndbufErrors", UDP_MIB_SNDBUFERRORS),
SNMP_MIB_ITEM("Udp6InCsumErrors", UDP_MIB_CSUMERRORS),
SNMP_MIB_ITEM("Udp6IgnoredMulti", UDP_MIB_IGNOREDMULTI),
SNMP_MIB_ITEM("Udp6MemErrors", UDP_MIB_MEMERRORS),
SNMP_MIB_SENTINEL
};
@ -137,6 +138,7 @@ static const struct snmp_mib snmp6_udplite6_list[] = {
SNMP_MIB_ITEM("UdpLite6RcvbufErrors", UDP_MIB_RCVBUFERRORS),
SNMP_MIB_ITEM("UdpLite6SndbufErrors", UDP_MIB_SNDBUFERRORS),
SNMP_MIB_ITEM("UdpLite6InCsumErrors", UDP_MIB_CSUMERRORS),
SNMP_MIB_ITEM("UdpLite6MemErrors", UDP_MIB_MEMERRORS),
SNMP_MIB_SENTINEL
};

View File

@ -637,6 +637,9 @@ static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
if (rc == -ENOMEM)
UDP6_INC_STATS(sock_net(sk),
UDP_MIB_RCVBUFERRORS, is_udplite);
else
UDP6_INC_STATS(sock_net(sk),
UDP_MIB_MEMERRORS, is_udplite);
UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
kfree_skb(skb);
return -1;